Why did Jesus wash His disciples’ feet?

"So after he had washed their feet, and had taken his garments, and was set down again, he said unto them, Know ye what I have done to you? Ye call me Master and Lord: and ye say well; for so I am. If I then, your Lord and Master, have washed your feet; ye also ought to wash one another's feet. For I have given you an example, that ye should do as I have done to you. Verily, verily, I say unto you, The servant is not greater than his lord; neither he that is sent greater than he that sent him. If ye know these things, happy are ye if ye do them." - John 13:12-17

Jesus, our Master and Lord humbled Himself as a servant and washed His disciple’s feet. Shortly after Jesus washed His disciple’s feet, He humbled himself and died for our sins on a tree.

"Let this mind be in you, which was also in Christ Jesus: who, being in the form of God, thought it not robbery to be equal with God: but made himself of no reputation, and took upon him the form of a servant, and was made in the likeness of men: and being found in fashion as a man, he humbled himself, and became obedient unto death, even the death of the cross." - Philippians 2:5-8

Just as Jesus forgives us, we must forgive our brothers and sisters. When we wash one another’s feet we have humbled ourselves and are demonstrating that we have no grudges against them. We show that we love one another.

"Be ye therefore followers of God, as dear children; and walk in love, as Christ also hath loved us, and hath given himself for us an offering and a sacrifice to God for a sweetsmelling savour." - Ephesians 5:1-2

When Mary washed Jesus’ feet with her tears, it was because she had been forgiven much. Because Jesus had forgiven her of much, she loved much. When our brothers and sisters have forgiven us, washing their feet is an outward sign of our love for one another.

"A new commandment I give unto you, That ye love one another; as I have loved you, that ye also love one another. By this shall all men know that ye are my disciples, if ye have love one to another." - John 13:34-35

As Jesus said, "If I then, your Lord and Master, have washed your feet; ye also ought to wash one another's feet. ... If ye know these things, happy are ye if ye do them." - John 13:14, 17